PeachParts Mercedes-Benz Forum - View Single Post

mach4 · #3 06-30-2017, 07:10 PM

Your gas tach signal comes from the ignition, which means your tach gauge in the dash will not work.

What I did on my swap (617->107) is swap in the EGR controller from the diesel. Mine was an '85, so it has a VR sensor on the bell housing that reads the teeth on the flywheel. The earlier engines had a tach pickup on the vibration damper and used a tach amp. In either case the trick is to swap in the tach gauge module into the cluster - mine bolted right in. Now your calibration will be completely off, so what I did was glue the diesel tach gauge face over the gas one and voila everything works. Now you technically don't need the EGR controller - there are threads describing how to hook the tach pickup directly to the tach module....just do a quick search.

One other thing - you may find that your transmission kickdown switch won't work. If your system is the same as mine, the fuel pump relay is required for power to the transmission solenoid (go figure!) The fuel pump relay gets a signal from the tach to turn on the fuel pump - no signal no power to the fuel pump (the idea is that if the engine is off the pump won't continue to pump, as in an accident which might sever a fuel line) You can jumper the relay to permanently power the transmission's kickdown.

If your speedometer doesn't work, there are work arounds for that too